This famous "last Tom Baker" episode of the popular
BBC show "Doctor Who" involves a city of whispering mathematicians
whose computations keep the universe running smoothly.
"The next broadcast story was a sequel, called Castrovalva, which was
more about the art of M.C.Escher but carried over the Logopolis
concept of reality-altering maths. Both stories were written by
Christopher Bidmead." (Contributed by Finn Clark.)